Determine % of customers who filled in a survey

I am trying to determine the % of residents in an apartment community that filled in a resident satisfaction survey. I have thousands of surveys and 50+ communities. Normally I would use a pivot table to determine the # of surveys filled in per community. I don't know how to take that result and divide it by the # of residents in that community, which would be held in a separate table. Can I do some sort of vlookup from the pivot table based on the community name, and divide the total number of residents by the Count for each community?

I've attached a small example file. Any help would be appreciated. Thank you.